In U.S. patent application Ser. No. 405,592, filed Aug. 5, 1982, there is disclosed the new sulfazecin related antibiotic compound of the formula: ##STR1##
This new antibiotic is similar in activity to the antibiotic azthreonam and useful in treating infectious diseases caused by gram negative microorganisms particularly P. aeruginosa.
The compound of formula I is prepared from an intermediate of the formula: ##STR2## where R is an amino protecting group; and M.sup.(+) is a cation.
The compound of formula II is converted to the compound of formula I by first cleaving the protecting group to form a compound of the formula: ##STR3## wherein M.sup.(+) is as above. and then reacting the compound of formula III with a compound of the formula: ##STR4## wherein X is halogen and R.sub.1 taken together with the oxygen atom to which it is attached forms an ester group convertible to an acid upon hydrolysis or hydrogenolysis
to form a compound of the formula: ##STR5## wherein X, M.sup.(+) and R.sub.1 are as above.
The compound of formula V is treated with a conventional deacylation agent and thereafter the ester group R.sub.1 is removed by either hydrolysis or hydrogenolysis to produce the compound of formula I.
A problem which has occurred with the above synthesis is that it has been difficult to synthesize the compound of formula II in its enantiomeric form efficiently and effectively from a readily available and economic starting material.